The present disclosure relates to methods and systems for generating surface data from volumetric data. The present disclosure also relates to methods of registering volumetric data to surface data.
Surface to surface registration is important for many different applications such as rapid prototyping, spatial calibration procedures, and medical applications. Generally, in medical imaging surfaces are either derived from acquired volumetric datasets or directly from surface based imaging systems. In the first case, volumetric datasets belonging to patient anatomy, such as those acquired from whole-volume 3D imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT), or ultrasound, are processed using algorithms such as marching cubes (Lorensen et al., 1987) to generate surfaces. With appropriate selection of intensity thresholds, the result is a surface representing a desired volume of interest. In the second case, surfaces of objects can be obtained by intrinsically surface based imaging such as optical range finding techniques like structured light imaging and laser range finding. With these techniques, the relative position of the surface topology imaging system to the object to be imaged determines which part of the surfaces will be visible to the imaging system and hence reconstructed.
Surfaces generated through marching cubes and related algorithms can be registered to other surface topology dataset using techniques such as iterative closest point, where the purpose of this registration is to align objects from different coordinate systems such that a spatial relationship may be established between the coordinate systems (e.g. from different imaging modalities). This has important clinical applications, such as in surgical navigation and other image-guided therapies.